JTAG TAP Controller Instruction decoder output lines

[sunidrak]

hi

Can any body plz explain the TAP controller IR decoder output lines connections to the various MUXs in TAP controller.

In the below Diagram the MUX at the output port has a select line . From where that select line will come is it come from IR-Decoder . IF from IR decoder then how the IR-Decoder are connected to various mux ?

**broken link removed**

 

[maulin sheth]

Hello,

Can you please let us know that which are those muxes which are coming from output lines of IR decoder? Those muxes are part of Boundary scan cell or something else?
Is it creating any issue/problem in design?

 

[sunidrak]

Hello,

Can you please let us know that which are those muxes which are coming from output lines of IR decoder? Those muxes are part of Boundary scan cell or something else?
Is it creating any issue/problem in design?

It is that MUX which is present in each Boundary cell which connects or disconnects the Boundary cell register from the design logic or from primary input pins.

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The same MUX that in previous image is in this image (MUX with mode as select line )